Mark Webber insists it's too early to draw any conclusions from the first two pre-season tests.
Ferrari set the pace during the first test in Valencia, but Mercedes, McLaren and Red Bull have all impressed during various stages of the second session in Jerez.
Webber, who was driving the RB6 for the first time in Jerez this week, says it would be foolish to read anything into the times that were set in the first two tests.
"There are a lot of teams doing a similar job at the moment," he told the official F1 website. "It is hard to read any more into it than that. We have a lot of variety in performance at the moment because of the different fuel loads obviously.
"We will see a difference of something like five seconds per lap from the start of the race to the end of the race. That is massive. And what I see is that people are testing different parts of a race, so it's almost impossible to say who is doing what. We are focusing on ourselves at the moment.
"I would not want to predict who is really on top. Kobayashi was doing fantastic times on Thursday, and the (BMW Sauber) car looks amazing, but how much fuel was he on? What is his time worth? It's the fuel that makes the car look so different."
The season kicks off in Bahrain in a month's time and Webber is hoping it will be a 1-2 finish for Red Bull.
"I like to believe that we are going to be there [on the podium]," he said. "Let's make it that I win, Sebastian is second and Fernando [Alonso] third!"
